Neutrophil emigration is mediated by adhesion proteins that are highly expressed on the endothelial surface during inflammatory processes in the brain. Intercellular adhesion molecule-1 (ICAM-1) is an inducible adhesion molecule that binds to leukocyte integrins and facilitates neutrophil adhesion and transendothelial migration. To study the role of ICAM-1 during ischemia and reperfusion in the brain, we analyzed the effect of transient focal cerebral ischemia in ICAM-1-deficient mice generated by gene targeting in embryonic stem cells. Transient focal ischemia was induced by occluding the left middle cerebral artery for 3 hours followed by a 21- or 45-hour reperfusion period. When compared with their wild-type littermates, ICAM-1-deficient mice were less susceptible to cerebral injury as demonstrated by a 5.6- or 7.8-fold reduction in infarction volume, respectively. These data support the premise that neutrophil adhesion in ischemic areas may be deleterious and that ICAM-1 deficiency reduces neurological damage after transient focal cerebral ischemia.

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Children undergoing neurosurgical resection are at high risk for postoperative nausea and vomiting. Ondansetron, a selective serotonergic (5-HT3) antagonist, is effective in reducing postoperative vomiting in several high-risk populations. In a prospective, randomized study, we compared the prophylactic use of intravenous ondansetron, 0.15 mg/kg, versus placebo for the prevention of emesis in 60 children, aged 2-18 yr, undergoing craniotomies for resective procedures. Patients with preoperative emesis were excluded from the study. All patients were tracheally extubated at the conclusion of surgery, and each episode of emesis during the first 24 postoperative hours was recorded. For the entire 24-h interval, the incidence of emesis in children who received ondansetron (57%) was not significantly different from that in those who received placebo (66%); however, in the first 8 h, the incidence was 25% (ondansetron) vs 44% (placebo) (P = not significant). In those receiving placebo, there was no difference in emesis between patients undergoing operations above versus below the tentorium. Although our sample size was too small to completely exclude any beneficial effect, ondansetron appears ineffective in preventing postoperative emesis in this patient population.

Managing children with diabetes insipidus (DI) in the perioperative period is complicated and frequently associated with electrolyte imbalance compounded by over- or underhydration. In this study the authors developed and prospectively evaluated a multidisciplinary approach to the perioperative management of DI with a comparison to 19 historical control children. Eighteen children either with preoperative DI or undergoing neurosurgical operations associated with a high risk for developing postoperative DI were identified and managed using a standardized protocol. In all patients in whom DI occurred during or after surgery, a continuous intravenous infusion of aqueous vasopressin was initiated and titrated until antidiuresis was established. Intravenous fluids were given as normal saline and restricted to two thirds of the estimated maintenance rate plus amounts necessary to replace blood losses and maintain hemodynamic stability. In all children managed in this fashion, perioperative serum sodium concentrations were generally maintained between 130 and 150 mEq/L, and no adverse consequences of this therapy developed. In the 24-hour period evaluated, the mean change in serum sodium concentrations between the historical controls was 17.6 +/- 9.2 mEq/L versus 8.36 +/- 6.43 mEq/L in those children managed by the protocol. Hyponatremia occurred less frequently in the children managed with this protocol compared with historical controls.